Bullet with aerodynamic fins and ammunition using same

ABSTRACT

An ammunition cartridge includes a tubular blank having a tail section in a shape of tail fins; a cap mated to a front section of the tubular blank; a solid core in a shape of a rod inside the tubular blank between the front and tail sections; and a casing having a propellant therein, the casing mated to the tubular blank. The core optionally includes an aerodynamic needle extending beyond the front portion. A portion of the aerodynamic needle inside the core is shaped as a spring. A muzzle wad and a washer are in contact with the muzzle wad and with the aerodynamic needle. The aerodynamic needle includes a portion embedded in the core that is shaped as a spring. The core includes a front portion and a rear portion, and a diameter of the front portion is larger than a diameter of the rear portion and is substantially equal to a diameter of the tubular blank. The cap can be conically shaped, round shaped, or can have a blunt front end, or can be shaped as two conical sections.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patent application Ser. No. 10/535,615, filed May 19, 2005, which is a U.S. National Phase of PCT/RU03/00501, filed on Nov. 18, 2003, which claims priority to Russian Patent Application No. 2002131148, filed on Nov. 20, 2002, which are all incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The invention relates to ammunition for firearms and pneumatic smooth-bore weapons and can be used for producing bullets for cartridges for hunting and sporting guns, as well as certain military applications.

BACKGROUND ART

An arrow-shaped bullet is known in the conventional art. This bullet is produced from a solid bar, the front part of which is tapered and the rear part of which is deformed to create an aerodynamic empennage (tail section) in the shape of longitudinal surfaces (see U.S. Pat. No. 3,846,878, issued on Nov. 12, 1974). The disadvantage of the method for producing such a bullet is its high manufacturing complexity.

Another method for producing an arrow-shaped bullet is known in the conventional art, see U.S. Pat. No. 5,515,785, issued on May 14, 1996. This method deforms the rear part of a tubular blank to create an aerodynamic empennage (tail section) and insert a functional filling (core) in the tube's cavity. The rear part of a tubular blank is deformed by inelastic deformation (plastic flow) of the tube's material, and the thickness of the tube's walls is altered.

After the empennage is formed, a core is inserted in the tube's cavity. A core can have a granular or jelly filling, e.g., a load released at the moment the bullet hits the target. This core is kept in the tube's cavity by friction or capillary forces. This method is not used for inserting solid cores, e.g., metal cores.

The disadvantage of this method is its high manufacturing complexity. Also, a bullet produced by this method cannot be used for commercial or sport hunting.

A cartridge comprising a shell having means for inflammation (a primer), a propelling charge, a bullet, and one or more wads is also known in the conventional art (see U.S. Pat. No. 5,239,928, issued on Aug. 31, 1993). The drawback of this cartridge is that it is not possible to use arrow-shaped bullets.

SUMMARY OF THE INVENTION

Accordingly, the present invention is related to a bullet with aerodynamic fins, a cartridge using same, and a method for manufacturing same that substantially obviates one or more of the disadvantages of the related art.

In one aspect, there is provided a method for producing an arrow-shaped bullet, the method comprising: inserting a solid core having a shape of a rod into a tubular blank; compressing a tail portion of the tubular blank to form a plurality of tail fins; at least partially inserting a cap into a front portion of the tubular blank; and compressing the front portion of the tubular blank to form a taper. A thickness of the walls of the tubular blank, throughout its length, is the same before and after both compressing steps. The cap can have a circular channel such that the front portion is compressed into the circular channel. The compressed front portion can have a plurality of ridges. The core can be made of metal, ceramic, plastic and metal-ceramic. A rear portion of the tubular blank can be compressed to a diameter that is smaller than a diameter of the core, prior to insertion of the core. The step of compressing the front portion can apply pressure to the tubular blank in a radial-tangential direction. A mold can be inserted into the rear portion of the tubular blank prior to compressing the rear portion, and then withdrawing the mold.

In another aspect, there is provided an ammunition cartridge including a tubular blank having a tail section in a shape of tail fins; a cap mated to a front section of the tubular blank; a solid core in a shape of a rod inside the tubular blank between the front and tail sections; and a casing having a propellant therein, the casing mated to the tubular blank. The core further includes an aerodynamic needle extending beyond the front portion. A portion of the aerodynamic needle inside the core is shaped as a spring. A muzzle wad and a washer are in contact with the muzzle wad and with the aerodynamic needle. The aerodynamic needle includes a portion embedded in the core that is shaped as a spring. The core includes a front portion and a rear portion, and a diameter of the front portion is larger than a diameter of the rear portion and is substantially equal to a diameter of the tubular blank. The cap can be conically shaped, round shaped, or can have a blunt front end, or can be shaped as two conical sections.

In another aspect, there is provided an ammunition cartridge including a tubular blank having a tail section in a shape of tail fins; a tapered front section of the tubular blank; and a solid core in a shape of a rod inside the tubular blank between the front and tail sections. The tapered front section includes a conical portion and a substantially round portion forward of the conical portion.

In another aspect, there is provided an ammunition cartridge including a tubular blank having a tail section in a shape of tail fins; a tapered front section of the tubular blank; a core in a shape of a rod inside the tubular blank between the front and tail sections; and pyrotechnic charge in the tail section.

Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE ATTACHED FIGURES

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 illustrates a method for producing a bullet according to the claimed method.

FIG. 2 illustrates a method of longitudinally clamping a blank between two crimping matrixes.

FIG. 3 illustrates a bullet with an extractor in the shape of an aerodynamic needle.

FIG. 4 illustrates the ammunition cartridge with muzzle wads and a bullet having an extractor in the shape of an aerodynamic needle and the ammunition in which the bullet is further fastened with a spring.

FIG. 5 illustrates a multi-bullet ammunition cartridge, with bullets fastened through the bottom wads, and single-bullet ammunition cartridge.

FIGS. 6-17 illustrate alternative embodiments of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

The object of the present invention is to remove the above drawbacks, namely, to develop an inexpensive relatively simple method for producing a bullet suitable for different kinds of targets and having low aerodynamic resistance, and also to develop an ammunition (cartridge) in which this bullet is used.

In order to achieve this object, a method for producing an arrow-shaped bullet includes the steps of deforming the rear part 103 (see FIG. 1) of a tubular blank 101 to create the aerodynamic empennage (tail section, or tail fins) and inserting a core 102 inside the front part 104 of the tubular blank. The core 102 is inserted in the tubular blank 101 before its deformation. The core 102 may be made of metal, ceramic, metal-ceramic, silicon, silicon oxide, plastics, and so on. The core 102 is fastened inside the blank 101 by a simultaneous deformation of the front and rear parts (104, 103) of the blank 102, to form a taper 150 on the front portion of the blank. The deformation is carried out by pressing the blank walls without altering the thickness thereof.

In general, the core is preferably made of a heavier material than the tubular blank. For example, the core 102 can be made of such metals as lead, copper, aluminum, and so forth. The core could be made of silicon oxide, plastics, ceramics, metal-ceramics, and so on. In the case of metal-ceramics, such a core can be made by pouring liquid ceramic material into a mold, and mixing it with metallic powder, and then baking it. Note that ceramics are usually hard, but relatively brittle, while the addition of metallic powder to the ceramic makes the overall structure both hard and relatively resistant to fracture.

Also, the core material can be made from pressed lead chips, or other metallic chips, manufacture waste products, such as small pieces of metallic wire that is “chopped up” into relatively smaller pieces, and then pressed together, and so on. As yet another option, as shown in FIG. 3, the extractor 308 can be made of the same material as the core 102. Alternatively, the core 102 can be made of a different material, and the extractor can have the shape of a spring. The spring can be made of a relatively stiff material, such as steel, while the remainder of the core is made of a softer material, such as lead or copper or aluminum.

A second object of the invention is a bullet produced by the method described above.

In the preferred embodiments of the invention, the deformation is carried out by longitudinally clamping the blank 101 between two crimping matrices 206, 207 (see FIG. 2). In order to keep the bullet inside the ammunition, and while it moves up the bore in the front part of the core 102, an extractor 308 is added to the core's material, and the core 102 is inserted in the blank 101 (see FIG. 3). The extractor 308 protrudes beyond the edge 309 of the blank 101, to make it possible to clamp the front part of the blank 101.

The extractor 308 is formed to be geometrically coupled with the muzzle wad 410 (see FIG. 4). When the core 102 is produced as a combination of a metal armoring rod and a soft metal filling (e.g., the filling can be made of lead, copper, aluminum and the like), the extractor 308 is made of the metal of the core's rod. As one option, a portion of the extractor 308 settles within of the core 102 (see 314 in FIG. 3).

The extractor 308 can be formed in the shape of an aerodynamic needle, in order to improve the bullet's aerodynamic properties. The core itself can also formed as a set of multiple elements in order to increase the impact effect of the bullet.

Another object of the invention is providing an ammunition cartridge 411 comprising a shell with a means of inflammation (primer), a propelling charge 412, one or more wads 410, and a bullet, including one or more bullets produced by the method described above.

To fasten a bullet in the ammunition 411, a securing spring 413 is further added that generally follows the shape of the bullet in the compressed state and thereby keeps the compressed shell. The spring 413 is fastened in the segments of the muzzle wad 410. The bullet is inserted therein. A spring 314 is elastically deformed by compressing it and fixing it inside the bullet and the spring 413 is inserted in the compressed state in the ammunition.

In order to fasten several bullets in a simple cartridge 411, a through bottom wad 516 is further produced having openings for the surfaces of the bullets' tail sections 105. The wad is inserted in the ammunition in such a way that the wad is inserted between the propelling charge and the bullets' central portions 308. The surfaces of the bullets' tail sections 105 fit into the wad's openings, and the bullets' tail sections 105 protrude beyond the wad's forward boundary and are inserted into the propelling charge's material. As shown in FIG. 5, the central portion of the blank 101 can be shaped as a polygon in cross-section, e.g., a triangle, hexagon, etc., or may be round/circular in cross-section, as shown in FIG. 1.

As yet a further option, the outer surface of the tubular blank 101 can have a low friction coating deposited thereon, for example PTFE (Teflon), in order to reduce the friction between the bullet and the barrel of the rifle, reduce the wear on the barrel, and increase the muzzle velocity. Additionally, the propellant 412 can be made of conventional (“black”) gunpowder, white gunpowder, smokeless gunpowder, etc., or can be made of gunpowder blocks, such as made of nitrocellulose, see element 412-2. Unlike conventional gunpowder, gunpowder blocks burn gradually, as the bullet moves forward in the barrel, improving performance. This increases bullet velocity, and reduces the load on the wad 410.

FIG. 7 illustrates another embodiment of the invention. In this case, the structure is similar to that illustrated in some of the earlier figures, however, a cap is added to the front portion of the bullet, see 715 in FIG. 7. The cap is pressed against the core 102, and then the forward portion of the tubular blank 101 is compressed against the cap, as shown in FIG. 7. Small ridges are formed on the outside, to hold the cap in place, and to improve the aerodynamics of the bullet. The cap can be made of any number of materials, such as plastic, rubber, and so forth. The material of the tubular blank 102 can be pressed either against the surface of the cap 715, or can be pressed into the cap.

Depending on the application, the plastic of the cap 715 can be either relatively soft, or relatively hard. It can also be made of the same material as the core, or made of different material with different properties.

FIG. 8 illustrates another embodiment of the invention, where the cap 816 is offset by a small gap relative to the core 102. As further shown in FIG. 8, the tubular blank 101 is pressed against the cap, to fix it into position. The cap can have a conical shape, see 816A, or can have a relatively blunt forward portion, see 816B.

FIG. 9A illustrates another embodiment of the invention, where the size of the core, labeled 920 in this figure, is larger (in diameter) than the diameter of the tubular blank. As further shown in this figure, the core 920 has an inner portion 922, which is inserted into the tubular blank, and an outer portion 924, which has a larger diameter, and extends substantially further forward. In the case of FIG. 9A, the inner portion 922 is affixed within the tubular blank by compressing the tubular blank 101 against the surface of the core 920. The embodiment shown in FIG. 9A is particularly useful if the core 920 is made of rubber, for non-lethal bullets. FIG. 9B illustrates another embodiment where the core 925 extents substantially beyond the tubular blank 101 (and has substantially the same outer diameter as the blank 101), where this embodiment can be used as an anti-aircraft bullet. In this case, the blank of the forward portion of the core 925 that projects beyond the front portion of the tubular blank 101 is at least as long as the length of the tubular blank 101, or even longer, and the portion of the core 925 that projects forward of the tubular blank 101 is substantially longer than the portion of the core 925 that is inside the tubular blank 101.

FIG. 10A illustrates another embodiment of the invention, where a small metallic includes a metallic washer 1030. The washer 1030 serves the same purpose as the securing spring 413 illustrated in FIG. 4, however, a washer is wider, and generally simpler to manufacture and assemble.

FIG. 11A illustrates another example of crimping matrices and rollers, designated 1140 in this figure, and which is used to compress the rear portion 103, so as to form the tail fins 105. The crimping matrices can have rollers, as illustrated in this figure, for a more symmetrical application of the force to the tubular blank.

FIG. 10B illustrates another embodiment of the invention, where the front portion of the tubular blank 101 is compressed into a generally conical shape. As shown in FIG. 10B, the application of the force is not radial, but somewhat tangential, or in a spiral manner. This avoids defects resulting from uneven deformation of the tubular blank, and results in a generally more symmetrical bullet.

FIG. 11B illustrates another embodiment of the invention, where the forward portion of the tubular blank is formed as a conical portion 1131, and a relatively thin portion 1130—somewhat similar to the extractor discussed earlier, which is used to reduce the aerodynamic resistance, however, formed as a unitary piece from the tubular blank 101.

FIG. 12 illustrates another embodiment of the invention, where the rear portion of the tubular blank is compressed to form tailfins, however, as shown in the bottom figure, there is no “empty space” left inside the rear portion of the tubular blank. An alternative embodiment is shown in FIG. 13, where the tail fins 105 are formed, however, some empty space, labeled 1335, remains in the rear portion of the tubular blank—in other words, the tail fins are not compressed to a point where their inner portions touch each other. As yet another embodiment, the empty space 1335 can be filled with a pyrotechnic material, for a tracer around. Alternatively, the space 1335 can be filled with a gas generating material, such as gunpowder, so as to reduce the air resistance of the bullet as it moves forward through air.

FIG. 14 illustrates another embodiment of the invention, where a mold 1440 is first insert into the rear portion of the tubular blank 101. The rear portion is then compressed, as discussed earlier, to form the tailfins, and then the mold 1440 is extracted.

FIG. 15 illustrates another embodiment of the invention, where a mold is inserted into the forward portion of the tubular blank 101. The mold 1545 is first inserted (and can either reach as far as the core 102, or can leave a gap between the mold 1545 and the core 102). The front portion of the tubular blank 101 is then compressed around the mold 1545. The mold is withdrawn, and a front papered portion 150 is then formed. As another alternative, the rear portion of the tubular blank can be compressed slightly, prior to insertion of the core, so that the core cannot move freely within the tubular blank.

In another embodiment of the invention, where, prior to forming the front paper of the tubular blank 101, an aerodynamic cone made of a relatively hard material, or hard plastic, is placed into the tubular blank. The tubular blank is then compressed, as shown in this figure. This can be useful in some rifles, where one of the bullets is directly behind another bullet (smooth-bore fowling pieces with tubular shop), such that the front conical, or sharp, portion touches the primer of the bullet just ahead of it, potentially damaging it. By making the cap blunt, or by making it soft, this problem is avoided.

FIG. 16 illustrates another embodiment, where a circular channel is formed in the core 102, see 1602 in FIG. 16. The forward portion of the tubular blank is then compressed into the channel 1602, forming the overall shape shown at the bottom of FIG. 17. This is done to both improve the aerodynamic characteristics of the bullet, and to insure that the material of the core and the cap does not crack or fracture when the compression occurs.

FIG. 17 illustrates another embodiment, where the cap, labeled 1702, is formed as a double-cone shape. The material of the tubular blank is then compressed around one of the conical portions, forming the structure shown in FIG. 17.

Having thus described preferred embodiments, it should be apparent to those skilled in the art that certain advantages of the described method and apparatus have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims. 

1. A method for producing an arrow-shaped bullet, the method comprising: inserting a solid core having a shape of a rod into a tubular blank; compressing a tail portion of the tubular blank to form a plurality of tail fins; at least partially inserting a cap into a front portion of the tubular blank; and compressing the front portion of the tubular blank to form a taper.
 2. The method of claim 1, wherein a thickness of the walls of the tubular blank, throughout its length, is the same before and after both compressing steps.
 3. The method of claim 1, wherein the cap includes a circular channel such that the front portion is compressed into the circular channel.
 4. The method of claim 1, wherein the compressed front portion includes a plurality of ridges.
 5. The method of claim 1, wherein the core includes any of metal, ceramic, plastic and metal-ceramic.
 6. The method of claim 1, further comprising compressing a rear portion of the tubular blank to a diameter that is smaller than a diameter of the core, prior to insertion of the core.
 7. The method of claim 1, wherein the step of compressing the front portion applies pressure to the tubular blank in a spiral direction.
 8. The method of claim 1, further comprising inserting a mold into the rear portion of the tubular blank prior to compressing the rear portion, and then withdrawing the mold.
 9. The method of claim 1, further comprising compressing a portion of the tubular blank prior to insertion of the core so that the core cannot move freely within the tubular blank.
 10. A method for producing an arrow-shaped bullet, the method comprising: inserting a solid core having a shape of a rod into a tubular blank; inserting a first mold into the front portion of the tubular blank; compressing a tail portion of the tubular blank to form a plurality of tail fins; withdrawing the first mold; inserting a mold into the front portion of the tubular blank; compressing the front portion of the tubular blank; and withdrawing the second mold.
 11. An ammunition cartridge comprising: a tubular blank having a tail section in a shape of tail fins; a cap mated to a front section of the tubular blank; a solid core in a shape of a rod inside the tubular blank between the front and tail sections; and a casing having a propellant therein, the casing mated to the tubular blank.
 12. The ammunition cartridge of claim 11, wherein the core further comprises an aerodynamic needle extending beyond the front portion.
 13. The ammunition cartridge of claim 12, wherein a portion of the aerodynamic needle inside the core is shaped as a spring.
 14. The ammunition cartridge of claim 13, further comprising an aerodynamic needle extending from the core and beyond the front portion.
 15. The ammunition cartridge of claim 12, further comprising a muzzle wad, and a washer in contact with the muzzle wad and with the aerodynamic needle.
 16. The ammunition cartridge of claim 12, wherein the aerodynamic needle includes a portion embedded in the core that is shaped as a spring.
 17. The ammunition cartridge of claim 12, wherein the core includes a front portion and a rear portion, and wherein a diameter of the front portion is larger than a diameter of the rear portion and is substantially equal to a diameter of the tubular blank.
 18. The ammunition cartridge of claim 11, wherein the cap is conically shaped.
 19. The ammunition cartridge of claim 11, wherein the cap has a blunt front end.
 20. The ammunition cartridge of claim 11, wherein the cap is shaped as two conical sections.
 21. The ammunition cartridge of claim 11, wherein the propellant includes both fast-burning gunpowder and gunpowder blocks.
 22. The ammunition cartridge of claim 11, further comprising a metal armoring rod and a soft metal filling inside the tubular blank, the metal armoring rod shaped into an extractor-needle.
 23. The ammunition cartridge of claim 11, further comprising an aerodynamic needle projecting forward from the tubular blank, wherein the aerodynamic needle is formed by compression of a material of a forward portion of the tubular blank.
 24. The ammunition cartridge of claim 11, wherein the rear portion of the tubular blank is compressed so that there is substantially no space between the tail fins.
 25. The ammunition cartridge of claim 11, wherein the rear portion of the tubular blank is compressed so that there is empty space left between the tail fins.
 26. An ammunition cartridge comprising: a tubular blank having a tail section in a shape of tail fins; a tapered front section of the tubular blank; and a solid core in a shape of a rod inside the tubular blank between the front and tail sections, wherein the tapered front section includes a conical portion and a substantially round portion forward of the conical portion.
 27. An ammunition cartridge comprising: a tubular blank having a tail section in a shape of tail fins; a tapered front section of the tubular blank; a core in a shape of a rod inside the tubular blank between the front and tail sections; and pyrotechnic charge in the tail section. 